Automatic stop mechanism for talking-machines



H. L. TUNISON. AUTOMATIC STOP MECHANISM FOR TALKING MACHINES.

APPLICATION FILED JUNE 17, 1919. 1,385,407. Patented July 26, 1921.

2 SHEETS-SHEET I.

"Mill llllll A %1; 14 autumn H. L. TUNISON.

AUTOMATIC STOP MECHANISM ron TALKING MACHINES. APPLICATION FILED JUNE17, I919.

Patented July 26, 1921.

2 SHEETS-SHEET 2- UNITED STATES PATENT OFFICE."

HAROLD L. TUNISO'N, OF UPPER MONTCLAIR, NEW JERSEY, ASSIGNOR TO FRANK L.

DYER, OF MONTCLAIR, NEW JERSEY.

AUTOMATIC STOP MECHANISM FOR TALKING-MACHINES.

Application filed June 17,

To all whom it may concern Be it known that I, HAROLD L. TUmsoN, acitizen of the United States, residing at Upper Montclair, in the countyof Essex, State of New Jersey, and have a post-ofiice address at No. 219Alexander avenue, Upper Montclair, N. J have invented certain new anduseful Improvements in Automatic Stop Mechanism for Talking-Machines, ofwhich the following is a specification.

My invention relates to certain new and useful improvements in automaticstop mechanisms for talking machines, of the type in which the operationof the mechanism is controlled by the position of the tone arm which hasa generally diametric movement with respect to the record disk.

M improved automatic stop mechanism is adapted to be assembled as a partof any talking machine having a tone arm or other element partaking of arelatively transverse movement with respect to the record. Since thedevice is extremal simple and compact, it may also be manu actured andsold as a separate attachment capable of being applied to existing typesof talking machines.

My improvements are essentially mechanical and comprise a friction brakewhich, when released, will engage and prevent rotation of the turn tableor other record car rier, said brake being locked in a withdrawn ositionduring the playing of the record, ut being tripped or released when thetone arm or other controlling element has reached a predetermined pointtransversely of the record.

Automatic stop devices of this type, both electrical as well asmechanical, are of course, well known. Such stop devices, as heretoforesuggested, have been adjustable to accommodate records ofdifierentlength; or in other words, have been arranged to operate ortrip the brake mechanism at the desired point of the transverse travelof the tone arm regardless of the len th of the record. In the case ofan elect'rlcal device, it is not difiicult to set the stylus in the lastgroove of the record and to therefrom determine when the brake deviceshall be electrically tripped, whereby when the tone arm reaches a pointcorresponding with the last groove, a circuit will be closed to thusrelease the brake and arrest the rotation of the turn table or otherrecord carrier. Electr cal devices, while thus su ficiently accu-Specification of Letters Patent.

Patented July 26, 1921.

1919. Serial No. 304,754.

rate, are relatively complicated, likely to get out of order, more orless clumsy in appearance, and, of course, they fail to work if anyderangement occurs in the electrical circuit or in the battery or in thecontacts.

Automatic stop mechanism, as heretofore suggested, of the mechanicaltype, have been slmple 1n construction, compact in appearance and ruggedin operation, but they have lacked accuracy of adjustment. With somemechanical stops the brake has been locked in a withdrawn position byvarious arrangements of triggers which are adapted to be released by themovement of the tone arm or other element as the same approaches thepoint relative to the record where the turn table or other recordcarrier is to be arrested. With the rior mechanical devices with which Iam amiliar, the arrangement is such that the adjustment point is that atwhich the tone arm engages the tripping mechanism, and therefore thereis necessarily a further movement of the tone arm before the actualtripping takes place. Obviously the adjustment is very delicate becausethe lateral travel of the stylus is of the order of one one-hundredth ofan inch for each rotation of the record, and this lateral travel is, ofcourse, proportionally diminished if the tone arm engages the brake tripat a point intermediate of its pivot and its free end. With these priormechanical devices, the attempt has been made to so make the adjustmentthat the brake will be actuated at the instant corresponding with thelast roove of the record. This, however, is pure y a matter of guess;ordinarily the operator engages the stylus three or four grooves shortof the last groove and sets the release mechanism to correspond with thepoint thus selected; then, as the tone arm nears the completion of therecord at the point selected, it will commence to operate the trigger,the expectation being when the record has been completely played and thestylus is in the last groove the brake will be released so as to arrestrotation of the turn table. Obviously this human factor is unreliable;if the mechanism is set to operate too far in from the last groove, thebrake will be released and the turn table stopped before the record hasbeen completely played; on the other hand, if not set far enough in fromthe last groove, the brake mechanism is liable not to operate at all.

' ustment is reached and Furthermore, it is a diflicult matter, even atbest, to select the proper groove where the adjustment is to be madeowing to the minute size of the grooves.

So far as I am aware, no one has hereto foresuggested a mechanicaldevice by which the brake mechanism may be set to operate with thestylus in the last groove of the record and will operate with certaintyand accuracy when the stylus has reached the point at which theadjustment was made. Thisresult I accomplish with my present im-:.provements. To this "end, I have designed an improved brake mechanismin which when the'l stylus'i's engaged with the last groove of therecord (or, of course, any other point where the record is to bestopped) and the gb'rake mechanism is adjusted with re- (spect to thetone arm at that indentical point, the adjustment will correspond to thetripping-point of the trigger, or, in other words, willcorrespond to theexact instant where the brake will be released. Having thus determinedthe tripping point of the brake releasing mechanism, I so coordinate theparts thatwhe'nthe tone arm is moved to the commencement of the recordthe trigger will be moved a'utomatically into position to receive thebrake mechanism and hold it in a withdrawnposition. Thereupon, as thetone arm progresses transversely across the face of'the record, and asit nears the end of the record, it eommences 'to gradually operate thetrigger, which will be finally released at the instant corresponding tothe precise pointof original adjustment. This capacity ofmyimprovedmechanism of automatically bringing-the trigger into operative positionto engage the brake mechanism provides a v'ery'accurate mechanicaldetermination of the movement which thetone arm shall have in trippingthe releasing mechanism; or, in other words, I determine mechanicallyand automatically the extent to which the tone arm shall move inreleasing the trigger, whereas, with devices as heretofore proposed,this determination has been a matter of guess work on the part of theoperator who engages the stylus a sufiicient distance in ward from theend of therecord to provide for the tripping ofthe trigger, as I haveexplained. The essential distinction between my-improved stop mechanismis that the poin't'of adjustment or determination corres ends to thetripping point of thetrigger, 'WlllCll after its adjustment isautomatically brought into position to engage and withhold the brake,and thetone arm engages the "tripping mechanism before the point of adgradually with draws the trigger which releases the brake at thepointiofadjustment. With prior devices, the ipoint'of adjustment has been thatpoint where the tone arm engages the trip andcommences to release thetrigger, so that the further movement of the tone arm after passing thepoint of adjustment acts to release the trigger, which therefore freesthe brake at a point that the operator has to guess at as a matter ofexperience. This general idea of providing for the positioningofmechanism at a point corresponding to the final release of thetrigger, and the automatic movement of the trigger thereafter intoposition to lock the brake withdrawn, may be carried out by a variety ofmechanical devices all involving the same inventive thought.

lVith the preferred embodiment of the invention, I make use of a brakedevice having a trigger pin arranged to lock the brake in a withdrawnposition, said brake being spring actuated, whereby when the trigger pinis tripped the brake will be released to engage and arrest rotation ofthe turn table or other record carrier. I provide a trip ping leverwhich is adapted to engage and trip the trigger pin when the tone armhas been moved to the predetermined point, and with the preferred formof the device I also use a determining arm to which the tripping leveris pivoted, whereby when the tripping lever and determining arm aresimultaneously engaged with the tone arm in its i'iual positioncorresponding to the last groove of the record, the trigger pin will bein the position where it will release the brake. By frictional means thedetermining arm will remain in the position of its adjustment thuscorresponding to the releasing point of the brake, but the trippinglever being capable of independent movement with respect to thedetermining arm, when the tone arm is moved to the beginning of therecord, will be moved relatively to the determining arm so as to bringthe trigger pin in position to en gage and lock the brake in itswithdrawn position. As the tone arm nears the end oi its movement, itwill come in contact with the tripping lever and gradually move the samepivotally with respect to the determining arm, and when these two armsare thus brought into line the trigger pin will be released to thus tripthe brake. In other words, the distance the tripping lever moves withrespect to the determining arm is an exact distance determinedautomatically by the very engagement of the tripping lever anddetermining arm simultaneously with the tone arm in its final position.

It is not necessary to use a separate tripping lever and determining armas explained, since it is possible to use only a single arm performingthe functions of the two. lVhen such a single arm is used it is firstbrought into engagement with the tone arm to determine the trippingpoint, and then when the tone arm is moved to begin playing the record,the combined tripping and determining arm partakes of an inde pendentauxiliary movement, as a result of which the trigger in is moved intoposition to lock the bra e.

Both forms of the invention are illustrated in the accompanying drawingsformin part of. this specificati0n,'and in which, igure 1 is a plan viewshowing the conventional representation of a talking machine record,sound box and tone armwith my present improvements applied to the same.Fig. 2, an enlarged plan view, partly in section, of my improved stopmechanism. Fig. 3, a sectional view on an enlarged scale on the line'3,3 of Fig. 1 looking in the direction of the arrows. Fig. 4, a section onthe line 4, 4 of Fig. 2 on an enlarged scale. Fig. 5 a plan view, part1in section, of a modified arrangement in w ich a single arm is usedfordeterminin the tripping point and also for tripping t e brake, thesection being taken on the line 5, 5 of Fig. 6 looking in the directionof the arrows. Fig. 6, an end elevation of Fig. 5 showing in full linesthe position of the tone arm and pivoted determining-tripping arm in thetrip ing osition, and in dottedlines the positlon o the same parts whenthe tripping-determining arm has moved to cause the trigger pin to bemoved to lock the brake in its withdrawn position. Fig.7, a section onthe lines 7, 7 of Fig. 6 in the direction of the arrows, the brake beingtripped to stop the turn table. Fig. 8, an elevation, partly in section,corresponding to the dotted line position'of Fig. 6. Fig. 9, alongitudinal sectional view corresponding to Fig. 7, the brake being inits withdrawn position, and Fig. 10 a separate detail of the annulartoothed lower end of the determining-tripping arm. In all of the aboveviews corresponding parts are represented by the same referencenumerals.

Referring first to Fig. 1, the turn table 1 is provided with the usualcenter pin 2, on which is mounted the record 3. A tone arm 4 carries thesound box 5, having a st lus 6, cooperating with the record groove. ith

the preferred embodiment of my invention,

I use a brake lever 7 pivoted on a small circular plate 8, and having arubber bufier or shoe 9, adapted to engage the periphery of the turntable 1 when the brake 1s re leased to stop the record. The brake lever7 is actuated when tripped by the usual spring 10. In Fig. 1 the brakelever is shown as being tripped to arrest the rotation of the turntable, and in Fig. 2 the brake lever is illustrated in a withdrawnposition.. The plate 8 is formed with an up turned arm 10, into which ismounted a small spring barrel 1.1. The trigger pin 12 extends throughthe barrel 11, and a coiled spring 13 normally forces the trigger pin tothe position shown in Fig. 4. The trigger pin 12 is provided with a head14 thereon having a cam-like inner face, as shown. A determining arm 15is connected with the barrel 11, whereby the barrel acts as a pivot forsaid lever. spring washer 16 is interposed, and maintained undertension, be tween the face of the arm 10 and the cap 17 of the barrel.By reason of the spring washer 16, it will be seen that when thedetermining arm 15 is moved to any angular position it will remain inthat position frictionally. A tripping lever 18 is pivoted near thelower end of the determining arm 15, and is provided with an incline cam19 adapted to be forced into engagement with the cam surface of the head14 to thus withdraw the trigger pin and release the brake. When thetripping lever 18 is parallel with the determining arm 15 (see dottedlines Fig. 3) the cam 19 will have withdrawn the trigger pin 12 torelease the brake. This corresponds to the trippin position of thebrake. In operation, if it is desired to stop the record inthe lastgroove, the tone arm is moved to bring the stylus 6 into the lastgroove, which can be readil done by simply moving the stylus over tiesmooth inner portion-of the record until the stylus engages and isarrested by the last groove of the record. The determining arm 15 andtripping lever 18 are now moved simultaneously until they engage withthe tone arm. When this engagement takes place the trigger pin 12 willbe withdrawn. Having thus determined the point where the brake is tobereleased, the tone arm 4 is now moved toward the beginning of therecord and as it moves to the position shown in the full lines in Fig.3, the tripping lever 18 will be moved with respect to the determiningarm by the tension of the s ring 13 and the engaging cam surfaces. hispermits the trigger pin 12 to move to the locking posi tion shown inFig. 4. The brake lever 7 may now be moved, causing the finger 2Othereon to engage behind the end of the trigger pin (see Fig. 2) andthus lock the brake withdrawn. The movement of the tripper lever 18 withrespect to the determining arm 15 may be limited by a pin 21. The brakebeing thus locked in its withdrawn position, the turn table willcommence to move and the record will be played in the usual way. As thetone arm 4 approaches the end of the record it comes into contact withthe tripping lever 18 at the full line position, Fig. 3, and graduallymoves the said lever toward the position shown in dotted lines. When thetripping lever has been moved to its original position a of adjustment,corresponding to that of the determining arm 15, the cam 19 will havewithdrawn the trigger pin entirely to release the brake and permit thesame to be applied to thus arrest the turn table. It Will be obviousthat the extent through relationship between the determinin which thetripper arm 18 moves in thus releasing the brake is determined'automati-.cally and is always fixed and certain and also that therelease .pointis always prede- .,end.of the trigger pin, I prefer to employiterminedand exact. In case of wear on the to the record. For instance,the stylus lever .6 may, be 'engaged with the last groove and theadjusting screw 22 may be regulated to cause the brake to be tripped oneor two grooves inward from the last groove. Such .an adjustment may bedesirable where the inertia of the parts to be'arrested isrelativelygreat with respect to the braking effeet, and where twoorthree turns may be required to bring those parts to rest.

, In Figs. 5 to 10, inclusive, I illustrate a modified arrangementinvolving the same inventive thought, but wherein a single lever is usedhaving the double function of tripping the trigger pin as well asdetermining the point where the release-of the brake is to be effected.With this modification, the brake comprises a plunger 23 carrying atitsinner end a friction pad made of cork, rubber or similar material Abrake lever 25 pivoted to the plate 26 is provided with a finger 27entering a groove 28 in the plunger 23, whereby the lever 25 may bemoved tothe dotted line position shown in Fig. 5 towithdraw the brakeplunger.- A spring 29 actuates the lever 25 to apply the brake whenreleased. The plate 26 isprovided with an upturned portion 30 forming abearing for the plunger 23 and with a similar portion'31 forming abearing for a barrel '32. Where the plunger 23 passes through the'barrel32 it is made blade-like in cross section, as shown at 33, so that theplunger may move longitudinally with respect to thebarrel like a keyinaYale look, but rotary movement of the barrel will also rotate theplunger. A spring washer 34 is interposed between the upturned portion31 and a nut 35 to hold the barrel 32 in any angular )osition to whichit may be adjusted. single determining armand tripping lever 36 ismounted on the barrel 32 so as to be capable of independent angularmovement with respect to the barrel. This arm 36 is formed with aneye 37encircling the barrel'and constituting the pivot of'the arm, and it isalso provided with a groove 38 in which is located thefiattenedend ofthe plunger. The groove 38 is formed between the two teeth 39' and 4:0in the eye 37 ,(see Fig. 10),, and the flattened end of the plunger isformed with a notch 41 on its under side, which notch, when the brakeplunger is entirely withdrawn, will be brought into line with the tooth39, as shown in Fig. 9. With this modified form of the invention, thetone arm is first moved to the position where it is to be arrestedcorresponding generally with the last record groove, and the arm- 36 isthen moved, as shown in Fig. 6, into engagement with said tone arm.During this adjustment the brake plunger is in its released positionshown in Figs. 5 and 7. Having thus made the de sired determination, thetone arm is then moved toward the beginning of the record groove andthetnrn table is started by movingthe brake lever 25 into position shownin dotted lines in Fig. 5. This frees the turn table which thereuponcommences to rotate.

As long as the flattened portion oi the plunger 23 remains in the groove38, the plunger will not be locked in its withdrawn position, but assoon as the notch 11 conies into line with the tooth 39 the lever 36will then betree to moveby gravity to the position shown in dotted linesFig. 6. This brings the tooth 39 withinthe notch ll and locks the brakeplunger withdrawn. At the same time the tooth 40 coming in contact withthe shoulder 42 of the barrel 32 (see Fig. 8 limits the independentsecondary movement of the arm 36 from its position the brake will bereleased and will thus be impelled into contact with the turn table toarrest rotation thereof. Although it is possible, as explained, to carryout the invention by the use of a single arm performing the doublefunction of first determining the brake releasing point and then movingindependently to permit the locking of the brake, I prefer to use twoseparate arms as shown in Figs. 1 to 4: inclusive, because in this way asomewhat simpler arrangement can be constructed and moreover it becomespossible to readily provide for accurate adjustment to take up any wearby a simple adjusting screw such as 22.

Having now described my invention, what I claim as new therein anddesire to secure by Letters Patent is as follows:

'1.In a stop mechanism for talking machines, the combination with thetone-arm, ofa spring actuated brake, a trigger for locking the brake 1n1ts wlthdrawn position.

means whereby the trigger may be released by the tone-arm traversing therecord, and

means cooperating with the tone-arm for automatically determining thereleasing poinlil; of said trigger, substantially as set ort a 2. In astop mechanism for talking machines, the combination with the tone armand a s ring actuated brake of a trigger for normal y locking the brakein its withdrawn position, means actuated b the tone arm which traversesthe record 'or withdrawing the trigger to release the brake, meanscooperating with the tone arm for determining the releasing point ofsaid trigger, and means for automaticall moving the trigger intoposition to hold t e brake withdrawn after its releasin point has beendetermined, substantial y as set forth.

3. In a stop mechanism for talking machines, the combination with thetone arm of a spring actuated brake, a trigger pin for locking the brakein a withdrawn position, a determinin arm cooperatin with the tone armfor eterminin the point at which the trigger pin releases t e brake, anda triping lever carried by the determining arm or releasing the brakewhen the tripping osition is reached, substantially as set orth.

4. In a stop mechanism for talking machines, the combination with thetone arm of a 5 ring actuated brake, a trigger pin for loc 'ng the brakein a withdrawn position, a determinin arm cooperating with the tone armfor etermining the point at which the trigger pin releases the brake,and a tripping lever carried by the determining arm for releasing thebra e when the tripping position is reached, said tripping arm havingautomatic predetermined movement with respect to the determining arm toprovide for the engagement of the trigger pin with the brake,substantially as set forth.

5. In a stop mechanism for talking machines, the combination with thetone arm of a spring actuated brake, a trigger pin for locking the brakein a withdrawn position, a determining arm e06 erating with the tone armfor determining t e point at which the trigger pin releases the brake, atripping lever carried b the determining arm for releasing the bra ewhen the tripping position has been reached, and an adjustable stop forregulating the movement of the tripping lever with respect to thedetermining arm, substantially as set forth.

6. In a stop mechanism for talking machines, the combination with thetone arm, of a spring actuated brake, a barrel with friction means tohold it in any position of rotary adjustment, a trigger pin mounted lonitudinally in said barrel for locking the bra e withdrawn, a determiningarm cooperating with the tone arm, and connected to the barrel foradjusting its rotative position,

and a tripping lever pivoted on the arm for withdrawing the trigger pmto release the brake, substantially as set forth.

This specification signed and witnessed this 13th day of June, 1919.

HAROLD L. TUNISON.

Witnesses:

FRANK L. Damn, C. D. JORDAN.

